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  1. /*
  2.  * Copyright (c) 2009 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup libfs
  30.  * @{
  31.  */
  32. /**
  33.  * @file
  34.  * Glue code which is commonod to all FS implementations.
  35.  */
  36.  
  37. #include "libfs.h"
  38. #include "../../srv/vfs/vfs.h"
  39. #include <errno.h>
  40. #include <async.h>
  41. #include <ipc/ipc.h>
  42. #include <as.h>
  43. #include <assert.h>
  44. #include <dirent.h>
  45. #include <mem.h>
  46.  
  47. /** Register file system server.
  48.  *
  49.  * This function abstracts away the tedious registration protocol from
  50.  * file system implementations and lets them to reuse this registration glue
  51.  * code.
  52.  *
  53.  * @param vfs_phone Open phone for communication with VFS.
  54.  * @param reg       File system registration structure. It will be
  55.  *          initialized by this function.
  56.  * @param info      VFS info structure supplied by the file system
  57.  *          implementation.
  58.  * @param conn      Connection fibril for handling all calls originating in
  59.  *          VFS.
  60.  *
  61.  * @return      EOK on success or a non-zero error code on errror.
  62.  */
  63. int fs_register(int vfs_phone, fs_reg_t *reg, vfs_info_t *info,
  64.     async_client_conn_t conn)
  65. {
  66.     /*
  67.      * Tell VFS that we are here and want to get registered.
  68.      * We use the async framework because VFS will answer the request
  69.      * out-of-order, when it knows that the operation succeeded or failed.
  70.      */
  71.     ipc_call_t answer;
  72.     aid_t req = async_send_0(vfs_phone, VFS_REGISTER, &answer);
  73.  
  74.     /*
  75.      * Send our VFS info structure to VFS.
  76.      */
  77.     int rc = ipc_data_write_start(vfs_phone, info, sizeof(*info));
  78.     if (rc != EOK) {
  79.         async_wait_for(req, NULL);
  80.         return rc;
  81.     }
  82.  
  83.     /*
  84.      * Ask VFS for callback connection.
  85.      */
  86.     ipc_connect_to_me(vfs_phone, 0, 0, 0, &reg->vfs_phonehash);
  87.  
  88.     /*
  89.      * Allocate piece of address space for PLB.
  90.      */
  91.     reg->plb_ro = as_get_mappable_page(PLB_SIZE);
  92.     if (!reg->plb_ro) {
  93.         async_wait_for(req, NULL);
  94.         return ENOMEM;
  95.     }
  96.  
  97.     /*
  98.      * Request sharing the Path Lookup Buffer with VFS.
  99.      */
  100.     rc = ipc_share_in_start_0_0(vfs_phone, reg->plb_ro, PLB_SIZE);
  101.     if (rc) {
  102.         async_wait_for(req, NULL);
  103.         return rc;
  104.     }
  105.      
  106.     /*
  107.      * Pick up the answer for the request to the VFS_REQUEST call.
  108.      */
  109.     async_wait_for(req, NULL);
  110.     reg->fs_handle = (int) IPC_GET_ARG1(answer);
  111.    
  112.     /*
  113.      * Create a connection fibril to handle the callback connection.
  114.      */
  115.     async_new_connection(reg->vfs_phonehash, 0, NULL, conn);
  116.    
  117.     /*
  118.      * Tell the async framework that other connections are to be handled by
  119.      * the same connection fibril as well.
  120.      */
  121.     async_set_client_connection(conn);
  122.  
  123.     return IPC_GET_RETVAL(answer);
  124. }
  125.  
  126. void fs_node_initialize(fs_node_t *fn)
  127. {
  128.     memset(fn, 0, sizeof(fs_node_t));
  129. }
  130.  
  131. void libfs_mount(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_callid_t rid,
  132.     ipc_call_t *request)
  133. {
  134.     dev_handle_t mp_dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
  135.     fs_index_t mp_fs_index = (fs_index_t) IPC_GET_ARG2(*request);
  136.     fs_handle_t mr_fs_handle = (fs_handle_t) IPC_GET_ARG3(*request);
  137.     dev_handle_t mr_dev_handle = (dev_handle_t) IPC_GET_ARG4(*request);
  138.     int res;
  139.     ipcarg_t rc;
  140.  
  141.     ipc_call_t call;
  142.     ipc_callid_t callid;
  143.  
  144.     /* accept the phone */
  145.     callid = async_get_call(&call);
  146.     int mountee_phone = (int)IPC_GET_ARG1(call);
  147.     if ((IPC_GET_METHOD(call) != IPC_M_CONNECTION_CLONE) ||
  148.         mountee_phone < 0) {
  149.         ipc_answer_0(callid, EINVAL);
  150.         ipc_answer_0(rid, EINVAL);
  151.         return;
  152.     }
  153.     ipc_answer_0(callid, EOK);  /* acknowledge the mountee_phone */
  154.    
  155.     res = ipc_data_write_receive(&callid, NULL);
  156.     if (!res) {
  157.         ipc_hangup(mountee_phone);
  158.         ipc_answer_0(callid, EINVAL);
  159.         ipc_answer_0(rid, EINVAL);
  160.         return;
  161.     }
  162.  
  163.     fs_node_t *fn = ops->node_get(mp_dev_handle, mp_fs_index);
  164.     if (!fn) {
  165.         ipc_hangup(mountee_phone);
  166.         ipc_answer_0(callid, ENOENT);
  167.         ipc_answer_0(rid, ENOENT);
  168.         return;
  169.     }
  170.  
  171.     if (fn->mp_data.mp_active) {
  172.         ipc_hangup(mountee_phone);
  173.         ops->node_put(fn);
  174.         ipc_answer_0(callid, EBUSY);
  175.         ipc_answer_0(rid, EBUSY);
  176.         return;
  177.     }
  178.  
  179.     rc = async_req_0_0(mountee_phone, IPC_M_CONNECT_ME);
  180.     if (rc != 0) {
  181.         ipc_hangup(mountee_phone);
  182.         ops->node_put(fn);
  183.         ipc_answer_0(callid, rc);
  184.         ipc_answer_0(rid, rc);
  185.         return;
  186.     }
  187.    
  188.     ipc_call_t answer;
  189.     aid_t msg = async_send_1(mountee_phone, VFS_MOUNTED, mr_dev_handle,
  190.         &answer);
  191.     ipc_forward_fast(callid, mountee_phone, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
  192.     async_wait_for(msg, &rc);
  193.    
  194.     if (rc == EOK) {
  195.         fn->mp_data.mp_active = true;
  196.         fn->mp_data.fs_handle = mr_fs_handle;
  197.         fn->mp_data.dev_handle = mr_dev_handle;
  198.         fn->mp_data.phone = mountee_phone;
  199.     }
  200.     /*
  201.      * Do not release the FS node so that it stays in memory.
  202.      */
  203.     ipc_answer_3(rid, rc, IPC_GET_ARG1(answer), IPC_GET_ARG2(answer),
  204.         IPC_GET_ARG3(answer));
  205. }
  206.  
  207. /** Lookup VFS triplet by name in the file system name space.
  208.  *
  209.  * The path passed in the PLB must be in the canonical file system path format
  210.  * as returned by the canonify() function.
  211.  *
  212.  * @param ops       libfs operations structure with function pointers to
  213.  *                  file system implementation
  214.  * @param fs_handle File system handle of the file system where to perform
  215.  *                  the lookup.
  216.  * @param rid       Request ID of the VFS_LOOKUP request.
  217.  * @param request   VFS_LOOKUP request data itself.
  218.  *
  219.  */
  220. void libfs_lookup(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_callid_t rid,
  221.     ipc_call_t *request)
  222. {
  223.     unsigned first = IPC_GET_ARG1(*request);
  224.     unsigned last = IPC_GET_ARG2(*request);
  225.     unsigned next = first;
  226.     dev_handle_t dev_handle = IPC_GET_ARG3(*request);
  227.     int lflag = IPC_GET_ARG4(*request);
  228.     fs_index_t index = IPC_GET_ARG5(*request); /* when L_LINK specified */
  229.     char component[NAME_MAX + 1];
  230.     int len;
  231.  
  232.     if (last < next)
  233.         last += PLB_SIZE;
  234.  
  235.     fs_node_t *par = NULL;
  236.     fs_node_t *cur = ops->root_get(dev_handle);
  237.     fs_node_t *tmp = NULL;
  238.  
  239.     if (cur->mp_data.mp_active) {
  240.         ipc_forward_slow(rid, cur->mp_data.phone, VFS_LOOKUP,
  241.             next, last, cur->mp_data.dev_handle, lflag, index,
  242.             IPC_FF_ROUTE_FROM_ME);
  243.         ops->node_put(cur);
  244.         return;
  245.     }
  246.  
  247.     if (ops->plb_get_char(next) == '/')
  248.         next++;     /* eat slash */
  249.    
  250.     while (next <= last && ops->has_children(cur)) {
  251.         /* collect the component */
  252.         len = 0;
  253.         while ((next <= last) &&  (ops->plb_get_char(next) != '/')) {
  254.             if (len + 1 == NAME_MAX) {
  255.                 /* component length overflow */
  256.                 ipc_answer_0(rid, ENAMETOOLONG);
  257.                 goto out;
  258.             }
  259.             component[len++] = ops->plb_get_char(next);
  260.             next++; /* process next character */
  261.         }
  262.  
  263.         assert(len);
  264.         component[len] = '\0';
  265.         next++;     /* eat slash */
  266.  
  267.         /* match the component */
  268.         tmp = ops->match(cur, component);
  269.         if (tmp && tmp->mp_data.mp_active) {
  270.             if (next > last)
  271.                 next = last = first;
  272.             else
  273.                 next--;
  274.                
  275.             ipc_forward_slow(rid, tmp->mp_data.phone, VFS_LOOKUP,
  276.                 next, last, tmp->mp_data.dev_handle, lflag, index,
  277.                 IPC_FF_ROUTE_FROM_ME);
  278.             ops->node_put(cur);
  279.             ops->node_put(tmp);
  280.             if (par)
  281.                 ops->node_put(par);
  282.             return;
  283.         }
  284.  
  285.         /* handle miss: match amongst siblings */
  286.         if (!tmp) {
  287.             if (next <= last) {
  288.                 /* there are unprocessed components */
  289.                 ipc_answer_0(rid, ENOENT);
  290.                 goto out;
  291.             }
  292.             /* miss in the last component */
  293.             if (lflag & (L_CREATE | L_LINK)) {
  294.                 /* request to create a new link */
  295.                 if (!ops->is_directory(cur)) {
  296.                     ipc_answer_0(rid, ENOTDIR);
  297.                     goto out;
  298.                 }
  299.                 fs_node_t *fn;
  300.                 if (lflag & L_CREATE)
  301.                     fn = ops->create(dev_handle, lflag);
  302.                 else
  303.                     fn = ops->node_get(dev_handle,
  304.                         index);
  305.                 if (fn) {
  306.                     int rc;
  307.  
  308.                     rc = ops->link(cur, fn, component);
  309.                     if (rc != EOK) {
  310.                         if (lflag & L_CREATE) {
  311.                             (void)ops->destroy(fn);
  312.                         }
  313.                         ipc_answer_0(rid, rc);
  314.                     } else {
  315.                         ipc_answer_5(rid, EOK,
  316.                             fs_handle, dev_handle,
  317.                             ops->index_get(fn),
  318.                             ops->size_get(fn),
  319.                             ops->lnkcnt_get(fn));
  320.                         ops->node_put(fn);
  321.                     }
  322.                 } else {
  323.                     ipc_answer_0(rid, ENOSPC);
  324.                 }
  325.                 goto out;
  326.             }
  327.             ipc_answer_0(rid, ENOENT);
  328.             goto out;
  329.         }
  330.  
  331.         if (par)
  332.             ops->node_put(par);
  333.  
  334.         /* descend one level */
  335.         par = cur;
  336.         cur = tmp;
  337.         tmp = NULL;
  338.     }
  339.  
  340.     /* handle miss: excessive components */
  341.     if (next <= last && !ops->has_children(cur)) {
  342.         if (lflag & (L_CREATE | L_LINK)) {
  343.             if (!ops->is_directory(cur)) {
  344.                 ipc_answer_0(rid, ENOTDIR);
  345.                 goto out;
  346.             }
  347.  
  348.             /* collect next component */
  349.             len = 0;
  350.             while (next <= last) {
  351.                 if (ops->plb_get_char(next) == '/') {
  352.                     /* more than one component */
  353.                     ipc_answer_0(rid, ENOENT);
  354.                     goto out;
  355.                 }
  356.                 if (len + 1 == NAME_MAX) {
  357.                     /* component length overflow */
  358.                     ipc_answer_0(rid, ENAMETOOLONG);
  359.                     goto out;
  360.                 }
  361.                 component[len++] = ops->plb_get_char(next);
  362.                 next++; /* process next character */
  363.             }
  364.             assert(len);
  365.             component[len] = '\0';
  366.                
  367.             fs_node_t *fn;
  368.             if (lflag & L_CREATE)
  369.                 fn = ops->create(dev_handle, lflag);
  370.             else
  371.                 fn = ops->node_get(dev_handle, index);
  372.             if (fn) {
  373.                 int rc;
  374.  
  375.                 rc = ops->link(cur, fn, component);
  376.                 if (rc != EOK) {
  377.                     if (lflag & L_CREATE)
  378.                         (void)ops->destroy(fn);
  379.                     ipc_answer_0(rid, rc);
  380.                 } else {
  381.                     ipc_answer_5(rid, EOK,
  382.                         fs_handle, dev_handle,
  383.                         ops->index_get(fn),
  384.                         ops->size_get(fn),
  385.                         ops->lnkcnt_get(fn));
  386.                     ops->node_put(fn);
  387.                 }
  388.             } else {
  389.                 ipc_answer_0(rid, ENOSPC);
  390.             }
  391.             goto out;
  392.         }
  393.         ipc_answer_0(rid, ENOENT);
  394.         goto out;
  395.     }
  396.  
  397.     /* handle hit */
  398.     if (lflag & L_UNLINK) {
  399.         unsigned old_lnkcnt = ops->lnkcnt_get(cur);
  400.         int res = ops->unlink(par, cur, component);
  401.         ipc_answer_5(rid, (ipcarg_t)res, fs_handle, dev_handle,
  402.             ops->index_get(cur), ops->size_get(cur), old_lnkcnt);
  403.         goto out;
  404.     }
  405.     if (((lflag & (L_CREATE | L_EXCLUSIVE)) == (L_CREATE | L_EXCLUSIVE)) ||
  406.         (lflag & L_LINK)) {
  407.         ipc_answer_0(rid, EEXIST);
  408.         goto out;
  409.     }
  410.     if ((lflag & L_FILE) && (ops->is_directory(cur))) {
  411.         ipc_answer_0(rid, EISDIR);
  412.         goto out;
  413.     }
  414.     if ((lflag & L_DIRECTORY) && (ops->is_file(cur))) {
  415.         ipc_answer_0(rid, ENOTDIR);
  416.         goto out;
  417.     }
  418.  
  419.     ipc_answer_5(rid, EOK, fs_handle, dev_handle, ops->index_get(cur),
  420.         ops->size_get(cur), ops->lnkcnt_get(cur));
  421.  
  422. out:
  423.     if (par)
  424.         ops->node_put(par);
  425.     if (cur)
  426.         ops->node_put(cur);
  427.     if (tmp)
  428.         ops->node_put(tmp);
  429. }
  430.  
  431. /** Open VFS triplet.
  432.  *
  433.  * @param ops       libfs operations structure with function pointers to
  434.  *                  file system implementation
  435.  * @param rid       Request ID of the VFS_OPEN_NODE request.
  436.  * @param request   VFS_OPEN_NODE request data itself.
  437.  *
  438.  */
  439. void libfs_open_node(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_callid_t rid,
  440.     ipc_call_t *request)
  441. {
  442.     dev_handle_t dev_handle = IPC_GET_ARG1(*request);
  443.     fs_index_t index = IPC_GET_ARG2(*request);
  444.    
  445.     fs_node_t *node = ops->node_get(dev_handle, index);
  446.    
  447.     if (node == NULL) {
  448.         ipc_answer_0(rid, ENOENT);
  449.         return;
  450.     }
  451.    
  452.     ipc_answer_5(rid, EOK, fs_handle, dev_handle, index,
  453.         ops->size_get(node), ops->lnkcnt_get(node));
  454.    
  455.     ops->node_put(node);
  456. }
  457.  
  458. /** @}
  459.  */
  460.